Instruments for use during spine surgery

ABSTRACT

Surgical instruments and devices including drivers, inserters, and reducers. The driver includes a ratcheting mechanism configured to provide uni-directional motion when engaged. The inserter includes a rack, pinion, and cam system designed to secure an implant and release an implant in-situ. The reducer includes a geared system for persuading together surgical components and aligning misaligned vertebrae.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/153,946 filed on Oct. 8, 2018 (published as U.S. Pat. Pub. No.2019-0090916), which is a continuation of U.S. patent application Ser.No. 15/358,268 filed on Oct. 11, 2018 (now U.S. Pat. No. 10,123,826),which is a continuation of U.S. patent application Ser. No. 14/213,055filed Mar. 14, 2014 (now U.S. Pat. No. 9,532,814), which claims priorityto U.S. provisional application No. 61/783,652 filed Mar. 14, 2013(expired). The entire contents of these documents are incorporatedherein by reference in their entireties for all purposes.

FIELD OF THE INVENTION

The present disclosure generally relates to devices used in surgery.More particularly, the surgical devices include instruments and toolsfor spinal surgery and fixation procedures.

BACKGROUND OF THE INVENTION

Many types of spinal irregularities can cause pain, limit range ofmotion, or injure the nervous system within the spinal column. Theseirregularities can result from, without limitation, trauma, tumor, discdegeneration, and disease. Often, these irregularities are treated byimmobilizing a portion of the spine. This treatment typically involvesaffixing a plurality of fixation devices to one or more vertebrae andconnecting the devices to an elongate rod that generally extends in thedirection of the axis of the spine.

Treatment for these spinal irregularities often involves using a systemof fixation devices to attain stability between spinal segments.Instability in the spine can create stress and strain on neurologicalelements, such as the spinal cord and nerve roots. In order to correctthis, implants of certain stiffness may be implanted to restore thecorrect alignment and portion of the vertebral bodies. In many cases, afixation device along with a vertical solid member can help restorespinal elements to a pain free situation, or at least may help reducepain or prevent further injury to the spine.

Typically, fixation devices may include a bone fastener (e.g., bonescrew, hook, etc.) for coupling the fixation device to vertebra.Fixation devices further may include a coupling element (e.g., a tulipelement) for coupling the bone fastener to the vertical solid member(e.g., elongate rod). Clamp and/or wedge elements may be used to securethe bone fastener in the coupling element. A locking cap may be used tosecure the rod in the coupling element. In order for the elements of thefixation device to be secured, the rod may need to be seated firmly inthe coupling element. A variety of methods and instruments may be usedto maximize engagement between the rod and the coupling element andattachment of the fixation devices.

Traditionally, these types of spinal devices were installed viaopen-back surgery. This type of procedure tended to cause extensivetrauma to the patient, resulting in long and painful recovery times. Inrecent years, a shift has been made toward minimally invasive surgery(MIS) techniques. In minimally invasive surgery, the surgeon makes smallincisions and uses special tools to insert devices, observe progress ofthe operation, and perform other activities in the surgical site.Minimally invasive surgical techniques frequently result in much lessinjury to the patient and improved healing and recovery times. In aminimally invasive procedure, however, it may be more difficult for thephysician to insert and secure the fixation devices, maneuver the rod,or the like. There is a need for improved tools and instrumentation, forexample, suitable for use in minimally invasive procedures.

SUMMARY OF THE INVENTION

To meet these and other needs, a number of surgical instruments anddevices are provided. In particular, a surgical instrument having aratcheting mechanism for driving a fastening element (e.g., pediclescrews or other bony anchors) includes a secure lock with the addedadvantage of in-situ uni-directional tightening. A surgical instrumentmay include a number of mechanisms to increase the functionality andsafety for inserting a surgical device, such as an implant. A surgicalinstrument also includes one or more reducers suitable for persuadingtogether, for example, a rod and a seat recess of an orthopedic deviceor coupling element, such as a pedicle screw assembly, in order to alignmisaligned vertebrae.

According to one embodiment, a surgical instrument for driving afastening element (e.g., a driver) includes a ratcheting mechanism. Thesurgical driver includes an outer housing and a shaft contained withinthe outer housing. The shaft has a first end configured for engaging afastener and a second end configured for providing a rotational force.The surgical driver includes a locking element connected to the shaftand having an engaging face with a first plurality of ratchet teeth. Thelocking element is configured to move longitudinally along the shaft.The outer housing includes a handle having a contacting face with asecond plurality of ratchet teeth sized and dimensioned to correspondwith the first plurality of ratchet teeth of the locking element.

The locking element also includes a locking button disposed thereon andconfigured to engage the shaft such that when the locking button isdepressed, the first plurality of ratchet teeth on the engaging facecontact and mate with the second plurality of ratchet teeth on thecontacting face, and the ratcheting mechanism is engaged. The lockingelement may include a spring which surrounds the shaft and forces theratcheting mechanism to remain engaged. The shaft may include a notchsuch that when the locking button is engaged in the notch, the firstplurality of ratchet teeth on the engaging face teeth are separated adistance from the second plurality of ratchet teeth on the contactingface, and the ratcheting mechanism is not engaged.

According to another embodiment, a surgical instrument for inserting asurgical device includes a body having an outer housing and a handle.The outer housing has a longitudinal body with a channel extendingtherethrough and a distal tip configured to engage the surgical device.A shaft including a release shaft has a distal end configured to contactthe surgical device and a second opposite end. The shaft is housedwithin the channel of the outer housing, and the shaft includes a rackhaving a longitudinal body with a plurality of teeth. A pinion having awheel-like body with a plurality of teeth radially extending therefromis configured to mate with the plurality of teeth of the rack. A camhaving a generally circular body with at least one projection isrotatably attached to the pinion and the body. A trigger is coupled tothe handle and includes a linkage connecting the trigger to the secondend of the shaft. When the trigger is initially depressed, the linkagemoves the shaft and secures the surgical device to the distal tip. Whenthe trigger is fully depressed, the linkage moves the rack and rotatesthe pinion and the cam, which thereby moves the release shaft andreleases the surgical device.

According to another embodiment, a method of using an inserterinstrument includes the steps of: (a) unlocking the instrument bydepressing the safety lock; (b) connecting the surgical device to thedistal tip of the instrument by apply an axial force; (c) locking thesurgical device to the instrument by slightly depressing the trigger;(d) performing the surgical procedure; and (e) releasing the surgicaldevice from the instrument by fully depressing the trigger.

According to yet another embodiment, a surgical instrument for reducinga bone fastener toward a rod includes a reducing member, an outerlongitudinal member, and a handle. The reducing member extends between aproximal end and a distal end. A distal portion of the reducing memberis adapted to receive a portion of the bone fastener, and a proximalportion of the reducing member has a first plurality of gear teeth. Theouter longitudinal member is sized and shaped to receive the reducingmember. The handle includes at least one trigger element. The triggerelement has a second plurality of gear teeth configured to causetranslation of the reducing member with respect to the outerlongitudinal member when a force is applied to the handle.

The gear teeth of the trigger element may be directly or indirectly incontact with the gear teeth of the reducing member. In one embodiment,the second plurality of gear teeth on the trigger element are configuredto directly engage and mate with the first plurality of gear teeth onthe reducing member to cause the reducing member to move proximally. Inanother embodiment, a pinion gear is sandwiched between the gear teethof the reducing member and the gear teeth of the trigger element. Inparticular, the second plurality of gear teeth on the trigger elementare configured to contact and rotate the pinion gear, and the piniongear is configured to contact at least a portion of the first pluralityof gear teeth on the reducing member to cause the reducing member tomove proximally. The surgical instruments may include other features,such as a ratcheting mechanism on an end of the trigger element touni-directionally ratchet the reducing member.

BRIEF DESCRIPTION OF DRAWING

The invention is best understood from the following detailed descriptionwhen read in connection with the accompanying drawing. It is emphasizedthat, according to common practice, the various features of the drawingare not to scale. On the contrary, the dimensions of the variousfeatures are arbitrarily expanded or reduced for clarity. Included inthe drawing are the following figures:

FIG. 1 depicts a side view of an instrument for driving a fasteningelement according to one embodiment;

FIG. 2 shows a cross-sectional view of the driving instrument of FIG. 2;

FIG. 3 shows a close-up view of a portion of the driving instrumentshown in FIG. 1;

FIG. 4 shows a close-up view of a portion of the driving instrumentshown in FIG. 2 when the button is not engaged in the shaft;

FIG. 5 depicts a close-up view of the portion of the driving instrumentshown in FIG. 4 when the button is engaged with the shaft;

FIG. 6A shows a side view of an instrument suitable for inserting animplant according to one embodiment;

FIG. 6B shows a cross-sectional view of the inserter instrument shown inFIG. 6A;

FIGS. 7A and 7B show close-up views of portions of the inserterinstrument shown in FIG. 6B with the trigger in an expanded position;

FIGS. 8A and 8B show close-up views of portions of the inserterinstrument shown in FIGS. 7A and 7B with the trigger depressed;

FIGS. 9A-9C show alternate views of a retention shaft suitable for usewith the inserter instrument depicted in FIG. 6A;

FIGS. 10A and 10B show close-up views of the retention shaft and distaltip shown in FIGS. 9B and 9C, respectively;

FIGS. 11A-11C show components of a locking mechanism (when locked) usedat the distal tip of the retention shaft in the inserter instrumentdepicted in FIG. 6A;

FIG. 12 shows the locking mechanism depicted in FIG. 11A in an unlockedstate;

FIG. 13A depicts a side view and FIG. 13 B provides a top view of anembodiment of an instrument with a reducer;

FIGS. 14A-C depicts one embodiment of an instrument with a gearedreducer;

FIGS. 15A-C provide an alternative embodiment of an instrument with ageared reducer; and

FIG. 16 depicts yet another embodiment of an instrument with a threadedreducer.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the disclosure are generally directed to surgicalinstruments and devices including drivers, inserters, reducers, and thelike. The surgical devices may be adapted to permit insertion through aminimally invasive procedure or micro-incision. The surgical devices arealso especially suitable for spinal surgeries and procedures. Examplesof surgical procedures suitable for employing the surgical devicesdescribed herein include, but are not limited to, insertion andsecurement of interbody fusion devices, bone anchors, fixation devices,including rods, plates and cables, fasteners (such as screws and caps),artificial disks, hip stems, artificial ligaments, trochars forgastro-intestinal work, or any procedure operating on a patient.

As used herein and in the claims, the terms “comprising” and “including”are inclusive or open-ended and do not exclude additional unrecitedelements, compositional components, or method steps. Accordingly, theterms “comprising” and “including” encompass the more restrictive terms“consisting essentially of” and “consisting of” It is also noted that,as used in this disclosure and the appended claims, the singular forms“a,” “an” and “the” include plural referents unless the context clearlydictates otherwise. Furthermore, the words “proximal” and “distal” referto directions closer to and further away from a reference point,respectively. For example, an operator (e.g., surgeon, physician, nurse,technician, medical professional, etc.) may insert the instrument intothe patient with the tip-end (e.g., the distal end) of the device towarda patient's body.

According to one embodiment, FIGS. 1-5 depict alternate views of asurgical instrument 100 (also called a driver 100) suitable for drivingor securing a fastening element, such as a screw, cap, or the like. Thesurgical instrument 100 may be in the form of a screwdriver for theinsertion of pedicle screws or other bony anchors. The instrument 100may be similar to competitive drivers in function, but includes at leasta novel locking mechanism. Unlike traditional screwdrivers which maybecome loose during anchor insertion, the surgical instrument 100 allowsfor a simple lock and unlock mechanism while still allowing the surgeonto further tighten the driver without additional steps.

The surgical instrument 100 includes an outer housing 116. The outerhousing 116 has a body which is generally hollow and defines a channelextending longitudinally through it and is sized and shaped to receive ashaft 118 therein. The outer housing 116 may include one or more windows117 suitable for viewing the shaft 118. The shaft 118 has a first end(e.g., distal end 112) configured for engaging a fastener and a secondend (e.g., proximal end 114) configured for providing a rotational force(e.g., a torque). The shaft 118 may include one or more threadedportions 119, for example, proximate to the distal end 112. The threadedportion 119 may be configured to engage a portion of the fastener or anadditional threaded component, such as an extension from the fasteningelement (e.g., a tulip or yoke).

As is evident in FIGS. 1 and 2, the distal end 112 includes a tip 120suitable for engaging a fastener. The tip 120 may include any typicalscrewdriver bit, such as a Phillips screwdriver tip, a slot-head tip, aRobertson-head tip, an Allen-wrench tip, a hexagonal-head tip, a TORX®head tip, a key, or the like. The tip 120 may have any suitablecross-sectional configuration designed to engage with a fasteningelement. Suitable fastening elements include screws (e.g., bone screws,pedicle screws, or other bony anchors), caps, bolts, nuts, tulips,yokes, locking elements (e.g., for anti-backout prevention), etc. Thefastening elements may include those exemplified, for example, in U.S.Publication No. 2013/0018428, which is hereby incorporated by referencein its entirety for all purposes. The shaft 118 may have an instrumentinterface 115 shaped to receive torque from a driver (not shown). Theinstrument interface 115 may also have any suitable shape, such as apolygonal cross sectional shape, hexagonal shape, or the like, as neededto apply an appropriate torque or rotational force to the shaft 118.

As shown in FIG. 3, the surgical instrument 100 includes a lockingelement 130. The locking element 130 may include a generallycylindrical-shaped body, which is generally hollow, and defines achannel extending longitudinally therethrough. The locking element 130is sized and shaped to receive the shaft 118 and surrounds the shaft118. The locking element 130 may be connected to the shaft 118, forexample, such that it is able to rotate about the shaft 118 and/or movelongitudinally along the length of the shaft 118. As shown in FIG. 4,the locking element 130 may also house a spring 138, which is sleeved onthe shaft 118. The spring 138 pushes against one or more tabs 144 (e.g.,a generally cylindrical tab 144) extending from the shaft 118 in orderto move the locking element 130 distally toward the outer housing 116.

As seen in FIG. 3, the locking element 130 includes an engaging face 132with a first plurality of ratchet teeth 134. The outer housing 116includes a handle portion 122 having a contacting face 124 with a secondplurality of ratchet teeth 126. The ratchet teeth 126 of the contactingface 124 are sized and dimensioned to correspond with the firstplurality of ratchet teeth 134 of the engaging face 132 of the lockingelement 130. The ratchet teeth 126, 134 are also sized and dimensionedsuch that a ratcheting mechanism occurs when the contacting face 124 ofthe handle portion 122 contacts or engages the engaging face 132 of thelocking element 130. Accordingly, when the engaging face 132 of thelocking element 130 contacts and mates with the contacting face 124 ofthe handle portion 122, the shaft 118 is able to ratchet or rotate in auni-directional rotation.

The locking element 130 includes a locking button 136 integrated withand disposed within the locking element 130. The locking button 136 isconfigured to engage at least one notch 140 formed along the peripheryof the shaft 118. The notch 140 includes a flat face 146 such that whenthe locking button 136 is retained in the notch 140 (shown in FIG. 5);the locking element 130 is retained in position and unable to movelongitudinally along the length of the shaft 118. Thus, when the lockingbutton 136 is engaged and retained in the notch 140, the first pluralityof ratchet teeth 134 on the engaging face teeth 132 are separated adistance from the second plurality of ratchet teeth 126 on thecontacting face 124 and the ratcheting mechanism is not engaged. In thisconfiguration, the shaft 118 is able to freely rotate in both directions(e.g., clockwise and counterclockwise) to tighten or loosen thefastening element.

The locking button 136 may be engaged with the notch 140 (the ratchetingmechanism is not engaged and the instrument 100 is “unlocked”) orunengaged in the notch 140 (the ratcheting mechanism is engaged and theinstrument 100 is “locked”) by depressing the locking button 136. Aspring 142 may be configured to assist in engaging and unengaging thelocking button 136 in the notch 140. When the locking button 136 isdepressed, the locking button 136 is no longer secured in the notch 140and the spring 138 moves the locking element 130 distally toward theouter housing 116, the handle 122, and the contacting face 124. Thus,when the locking button 136 is not engaged in the notch 140 (as shown inFIG. 4), the first plurality of ratchet teeth 134 on the engaging face132 are contacting and mating with the second plurality of ratchet teeth126 on the contacting face 124 and the ratcheting mechanism is engaged.The spring 138 may be configured to keep the ratcheting mechanismengaged unless the locking button 136 is again depressed.

By way of example, with the driver 100 in the unlocked position, theuser can attach a screw by threading the instrument shaft 118 into thescrew. Once tight, the lock can be engaged by pressing the lockingbutton 136. The locking button 136 releases the locking element 130,which is forced forward via the spring 138. The locking element 130slidably engages with the threaded shaft 118. The locking element 130and, in particular, engaging face 132 will prevent counter-clockwiserotation, but still allows the instrument 100 to be further tightened.This is accomplished via the uni-directional ratchet. This design hasseveral benefits over the current technology including, for example, asecure lock with the added advantage of in-situ tightening without anadditional step.

According to another embodiment, FIGS. 6-12 depict alternate views of asurgical instrument 200 (also called an inserter 200) suitable forinserting a surgical device, such as an implant. In addition, thesurgical instrument 200 provides for a simple, highly repeatable methodfor in-situ implant assembly. The instrument 200 incorporates numerousmechanisms to increase the function and safety of the inserter 200,without complicating the process of assembly and providing a securemethod of assembly in-situ. Each component works together to create aninstrument 200 that provides the user with a safe and repeatableassembly method.

As shown in FIGS. 6A and 6B, the instrument 200 includes a body 216having an outer longitudinal housing or retention shaft 218, a handle220, and a trigger 222. The body 216 holds all of the components andkeeps them aligned as well as providing a palm support. The inserter 200may be attached or affixed to any suitable arms, handles, frames,devices, or the like known in the art. The handle 220 or handles(including trigger 222) may be configured such that an operator is ableto maneuver the inserter 200 in a suitable manner. In particular, thetrigger 222 may be connected to the handle 220 by coupling element 240,which allows for rotational motion such that the trigger 222 and thehandle 220 may be squeezed together and released apart. In addition, aspring 246 may be provided between the handle 220 and the trigger 222 toallow for the trigger 222 to maintain an expanded position unless aforce is applied. Thus, the handle 220 and the trigger 222 provide amechanism for application of a force.

The body 216 of the instrument 200 includes the outer longitudinalhousing or retention shaft 218. The retention shaft 218 includes agenerally cylindrical longitudinal body. The retention shaft 218 isgenerally hollow and defines a channel extending longitudinallytherethrough. The retention shaft 218 includes a distal tip 202 adaptedto receive and mate with a portion of an implant component, bonyfixation point, and/or bone fastener including a screw, tulip, yoke, orthe like. The retention shaft 218 is designed to accept the implant thatis to be delivered to the surgical site.

The distal tip 202 is mateable with the intended component, such that,when assembled, the distal tip 202 and the intended component create arigid or semi-rigid assembly. As shown in FIGS. 7B and 8B, the distaltip 202 includes an interior wall 206 which defines one or more catches208 that are adapted to mate with at least a portion of an implantcomponent, etc. For example, the catches 208 may have a shape thatcomplements or corresponds to the shape of the outer surface of theimplant component, bony fixation point, and/or bone fastener. Inparticular, an embodiment of the retention shaft 218, depicted in FIGS.9A-9C, is suitable to mate with a modular tulip. These catches 208 mayinclude a spring tab 204 and may include a ramped surface 210. Inparticular, two spring tabs 204 at the distal end 212 may form a snapfit between the implant and instrument 200. These tabs 204 flare open toaccept and hold the implant. These tabs 204 are pushed open by therelease shaft 244 when the trigger 222 on the handle 220 is fullydepressed, releasing the implant.

The retention shaft 218 is sized and shaped to receive a locking shaft242 and a release shaft 244 therein. In particular, the locking shaft242 is pinned to the linkage 224 such that when the linkage 224 moves(e.g., due to a small squeezing force), the linkage 224 moves linearlyin the opening 230 of the handle 220 to move the entire shaft 224distally and fully secure the implant. The locking shaft 242 provides anaxial force to internal components of the mating implant, rigidlyattaching the implant components together. The release shaft 244 andlocking shaft 242 may extend in any suitable configuration through theretention shaft 218 in order to perform the intended functions. Therelease shaft 244 is responsible for the bulk of the instrument 200function providing the lock and release features.

The release shaft 244 also moves through the body 216 via the linkage224 between the trigger 222 and the handle 220. A first end of thelinkage 224 is connected to a portion of the trigger 222 via a couplingelement 240, and a second end of the linkage 224 is connected to aportion of the handle 220 via another coupling element 240. Inparticular, the coupling element 240 provided at the second end of thelinkage 224 may be retained in a longitudinal opening 230 in the handle220. The longitudinal opening 230 allows for the rotational motionprovided by squeezing the trigger 222 to be converted to linear motionof the release shaft 244.

As shown in FIG. 7A, the release shaft 244 has an integrated rack 226and houses the pinion 232, cam 236, and locking shaft 242. Theintegrated rack 226 has a longitudinal body and includes a plurality ofteeth 228 on at least one side of the rack 226. The pinion 232 has awheel-like body with a plurality of teeth 234 positioned along theperiphery of the body and which radially extend outward. The cam 236include a wheel-like or substantially circular body and includes atleast one projection 238. The cam 236 is rotatably attached to thepinion 232, which rotates relative to the linear motion of the rack 226.The axial force is delivered through the rotation of cam 236. The piniongear 232 may be coupled with a coupling element to allow for a pivotpoint and rotational motion of the pinion 232 and the cam 236.

The pinion 232 translates the linear movement from the rack 226 to arotational motion of the cam 236. The pinion 232 is pinned to the body216 and rotates relative to the release shaft 244. Thus, the teeth 228of the integrated rack 226 are configured to contact and rotate thepinion 232, and the pinion 232 is configured to rotate the cam 236 tocause linear movement of the release shaft 244 and/or locking shaft 242.

When the trigger 222 is in an expanded configuration relative to thehandle 220, for example, as depicted in FIG. 7A, the locking shaft 242and release shaft 244 are in a retracted position. As is evident, theprojection 238 on the cam 236 is not contacting the release shaft 244.When the trigger 222 is partially depressed, the linkage 224 moveslinearly in the opening 230 of the handle 220 to move the locking shaft242 distally in order to provides an axial force to and rigidly securethe mating implant. FIG. 7B depicts the distal end 212 of the inserter200 when the trigger 222 is in the expanded configuration. With therelease shaft 244 in a retracted state, one or more tabs 250 do notextend beyond a distal face of the distal tip 202. Thus, if engaged, animplant would remain engaged with the retention shaft 218.

When the trigger 222 is completely depressed, as shown in FIG. 8A, thelinkage 224 continues to move linearly in the opening 230 of the handle220 and the teeth of the rack 226 mate with the teeth 234 on the pinion232 to rotate the pinion 232 and the cam 236. The projection 238 on thecam 236 rotates to contact and move the release shaft 244 distally toprovide the release shaft 244 in a fully extended position. A spring 248may also be provided around the release shaft 244 to move the releaseshaft 244 in the distal direction. FIG. 8B depicts the distal end 212 ofthe inserter 200 when the trigger 222 is in the compressed configurationand the release shaft 244 is extended. With the release shaft 244 in anextended state, the tabs 250 extend beyond a distal face of the distaltip 202. Thus, if previously engaged, an implant would become disengagedfrom the retention shaft 218.

By way of example, the surgical site may include a pedicle anchor oralternative means of bony fixation (e.g., sacral plate, lamina clamp,lamina band, etc.). The instrument 200 operates by first collecting animplant component (not shown). The implant component is attached to thedistal tip 202 of the inserter instrument 200, which is then moved to asurgical site. The implant is attached temporarily to the preferred bonyfixation method using axial force. Once the desired position isachieved, the trigger 222 on the handle 220 may be pulled, locking theimplant to the chosen fixation method. Pulling of the trigger 222 on thehandle 220 will also release the instrument from the implant in order toleave the implant securely assembled in-situ.

Unlike traditional devices which rely on snap-fits and materialproperties to ensure a safe method of assembly, the inserter 200 uses achange in implant state as well as mechanical force to ensure theimplant components are properly mated. For example, with the bonyfixation point already placed, the inserter 200 attaches to the matingcomponent and holds it securely. The implant is held in the retentionshaft 218 by displacing the spring tabs 204 on the sides of the shaft218. The instrument 200 is used to approximate the mating implant to thebony fixation point. The mating implant is temporarily attached usingaxial force. The implant is permanently attached by pulling the trigger222 of the instrument handle 220.

The action of pulling the handle 220 performs several operations. Thetrigger 222 of the handle 220 may actuate the linkage 224 attached tothe release shaft 244, which causes linear motion, collinear to theretention shaft 218. The release shaft 244 has an integrated rack 226housed within the body 216. This rack 226 is mated with a pinion gear232 which is rotatably mated with a cam 236 and the body 216. The piniongear 232 will rotate relative to the linear motion of the release shaft244, which rotates the cam 236. This cam 236 is slidably attached to thelocking shaft 242, which when rotated, provides axial force to thelocking shaft 242, locking the mating implant. The release shaft 244continues to articulate linearly until it comes in contact with tworamped surfaces 210 on the inside of the spring tabs 204. The releaseshaft 244 will deflect the spring tabs 204 allowing the mating implantto be released.

The inserter 200 may further include a safety lock 260. The safety lock260 is a separate mechanism that locks the instrument 200 unless thebony fixation point is within the mating implant body. The lock 260 mayhave any suitably shaped body and form, such as tubular, elongatedprojection, a pin, a protrusion, or the like which extends beyond thedistal end of the distal tip 202. The lock 260 protrudes into the matingimplant and must be pressed, releasing the instrument lock. Pressing thelock piston will articulate a separate piston via a pin slidermechanism, causing a motion approximately normal to the motion of thelock piston.

The safety lock 260 utilizes a pin 262 and follower 264 to provide thesafety lock 260 at the tip of the instrument 200. The lock 260 iscoupled to the pin 262 and positioned within the follower 264 via acoupling element 266, such as a pin. As best shown in FIG. 11C, the lock260 includes the follower 264 which is a non-linear opening formedtherein (e.g., an angled, v-shaped, or stepped configuration). Thefollower 264 opening is especially configured to translate the movementof the lock 260 in a proximal direction to a perpendicular movement forthe pin 262. In a locked state, the pin 262 is housed in an opening 264in the wall of the distal tip 202. When the pin 262 is engaged in theopening 264, as shown in FIG. 11A, the trigger 222 is locked and theinstrument 200 cannot be used. This prevents a user from using theinstrument 200 if it is not properly seated. When the safety lock 260 isdepressed (e.g., when an implant is secured thereto), as shown in FIG.12, the coupling element 266 follows the follower 264 and allows the pin262 to retract from the opening 264 in the distal tip 202. This enablesfull functionality of the instrument 200.

According to another embodiment, the instruments described herein may beprovided with a secure form of interaction between implants andinstruments. Although exemplified for inserter instrument 200, theattachment mechanisms described herein may be applied to any suitablesurgical instrument including, but not limited to, correction,reduction, persuasion, insertion, removal, manipulation (compression,distraction, etc.), instruments to implant interaction, instruments toinstrument interaction, implant to implant interaction, etc.

As shown in FIGS. 9A-9C, the retention shaft 218 includes the distal tip202, which is mateable with the intended component, such that, whenassembled, the distal tip 202 and the intended component create a rigidassembly. The distal tip 202 includes an interior wall 206 which definesone or more catches 208 that are adapted to mate with at least a portionof an implant component, etc. These catches 208 may be in the form of asolid ledge 252 and one or more spring cuts 254 to form a rigid form ofinteraction between the implant component and the instrument. The springcuts 254 and solid ledge 252 may help to address the issue of inadequateretention force and reduce the likelihood that the instrument becomesdisassociated from the implant. The implant component may containsimilar reciprocal ledges or projections to engage the solid ledge 252,for example.

The catches 208 may include a spring tab 204. One or more spring cuts254 may be formed through the instrument allowing the catch 208 to flexoutwardly and radially away from the instrument. The spring cut 254 maybe in the form of a U-shaped design to allow a greater area of the catch280 to deflect. The spring cut 254 may include one or more flat sectionsor portions or may be of any suitable shape, cross-section, or design.The spring cuts 254 may be designed to allow the spring tabs 204 to flexwhen the surgical device is secured or released from the instrument. Theother outer surfaces may be immovable while the spring tabs 204 allowthe implant to be inserted and released. Thus, the outer body remainsrigid relative to the holding features. By way of example, two springtabs 204 at the distal end 212 may form a snap fit between the implantand instrument. These tabs 204 flare open to accept and hold theimplant. The tabs 204 may also be pushed open when the implant isreleased.

The catches 208 may include one or more inner ledges 252 designed tomate with the surgical device. This allows for the mating implant to beinserted and retained securely. These form-fitting mating inner surfacesmay help to create a semi-rigid or rigid interface with the matingimplant. The catches 280 may also include the ramped surface 210 tofacilitate an axial insertion of the surgical device onto the instrument(e.g., a snap-fit). This design has several benefits including anenhanced implant/instrument interface including a more rigid connectionand simpler insertion and removal.

According to another embodiment, FIGS. 14A and 15A depict side views ofinstruments 300 (also called reducers 300) suitable for persuadingtogether a rod and a seat recess of an orthopedic device or couplingelement, such as a pedicle screw assembly including a fastener, tulip,yoke, or the like. In particular, the instruments 300 include reducinginstruments suitable for aligning misaligned vertebrae.

As shown in FIG. 14A, the instruments 300 include a reducing member 316,an outer longitudinal body 318, and a handle or grip made including afirst trigger element 320 and a second trigger element 322. The reducingmember 316 includes a generally cylindrical longitudinal body. Thereducing member 316 and has a working end 324 and a trigger end 326extending from a distal end 312 toward a proximal end 314.

In addition, the reducing member 316 is generally hollow and defines achannel extending longitudinally through it from the working end 324 tothe trigger end 326. The working end 324 of the reducing member 316 isadapted to receive a portion of a bone fastener including a tulip, yoke,or the like. In particular, the working end 324 is adapted to mate withan instrument or device, such as a fastener (e.g., a screw), a tulip, arod, or the like. In this regard, the working end 324 may be forked andmade up of a pair of opposing prongs 330, 332. The prongs 330, 332 eachhave an interior wall which defines one or more catches (not shown) thatare adapted to mate with at least a portion of a pedicle screw assembly.These catches may include the spring tabs 204 and ramped surfaces 210,as discussed above. For example, the catches may have a shape thatcomplements or corresponds to the shape of the outer surface of areceiver element, fastener, tulip, yoke, or coupling element.

The outer longitudinal member 318 has a body which is generally hollowand defines a channel extending longitudinally through it and is sizedand shaped to receive the reducing member 316 therein. The outerlongitudinal member 318 may be contiguous with the first or secondtrigger elements 320, 322. As shown in FIG. 14A, the longitudinal member318 may be a single continuous extension of the second trigger element322. In the embodiment shown in FIG. 15A, the longitudinal member 318may be a single continuous extension of the first trigger element 320.The orientation of the outer longitudinal member 318 to the first andsecond trigger elements 320, 322 may depend on the approach taken by thesurgeon. For example, in the embodiment depicted in FIG. 14A, the firstand second trigger elements 320, 322 are generally co-planar with thelongitudinal member 318 and reducing member 316. In FIG. 15A, on theother hand, the first and second trigger elements 320, 322 are generallyperpendicular with respect to the longitudinal member 318 and reducingmember 316.

The reducing member 316 may be able to translate or move with respect tothe outer longitudinal member 318 when a force is applied to the handle,namely, to either or both of the first and second trigger elements 320,322. In particular, when a force is applied to either or both of thefirst trigger element 320 and the second trigger element 322 thereducing member 316 may move proximally, for example, with respect tothe longitudinal member 318 or generally with respect to the instrument300. By moving in this manner, the reducing member 316 is able tore-align one or more misaligned vertebrae and move a seat recess of anorthopedic device or coupling element, such as a pedicle screw assemblyincluding a fastener, tulip, yoke, or the like, into position to becoupled to a rod or the like.

The reducing member 316 proximate to the trigger end 326 has a firstplurality of gear teeth 336. For example, the reducing member 316 maycomprise a substantially flat portion 334 proximate to the trigger end326. The flat portion 334 may comprise the first plurality of gear teeth336. These gear teeth 336 may extend along the entire flat portion 334or a portion thereof. Similarly, the first plurality of gear teeth 336may extend from the trigger end 326 along a length of the reducingmember 316 or may extend along a portion thereof.

As can be seen in FIGS. 14B and 15B and with close up views in FIGS. 14Cand 15C, the handle of the instrument 300 includes at least a firsttrigger element 320 and a second trigger element 322, and at least oneof the trigger elements 320, 322 includes a second plurality of gearteeth 338. The first and second trigger elements 320, 322 are coupledtogether with coupling element 340, which acts as a pivot point. Thus,when the first and second trigger elements 320, 322 are moved relativeto one another or squeezed together in the direction of arrows A (seeFIG. 14C), the movement of the trigger elements 320, 322 translates tolinear motion for the reducing member 316 due to coupling element 340and gear teeth 336, 338. The force causes movement of the reducingmember 316 relative to the outer longitudinal body 318 such that thereducing member 316 slides through the outer longitudinal body 318 inthe direction of arrow B. The process can be a single, continuousmovement or alternatively can be a step-wise movement due to the use ofa ratchet 350 described below.

As depicted in FIG. 14C, the second plurality of gear teeth 338 may beconfigured to directly engage and mate with the first plurality of gearteeth 336. Thus, when the first and second trigger elements 320, 322 aremoved relative to one another (e.g., squeezed), the first triggerelement 320 rotates in the direction of arrow C and the reducing member316 moves proximally in the direction of arrow B. After the vertebrae orelement has been reduced, the reducing member 316 is able to return toits original position such that the reducing member 316 moves distallyin a direction opposite to arrow B and the first trigger element 320rotates in a direction opposite to arrow C to return the first andsecond trigger elements 320, 322 to an expanded position.

In the embodiment depicted in FIG. 15C, the instrument 300 furtherincludes a pinion gear 342. The pinion gear 342 has a wheel-like bodywith a plurality of teeth 344 positioned along the periphery of the bodyand which radially extend outward. The pinion gear 342 may be coupledwith coupling element 346 to allow for a pivot point and rotationalmotion of the pinion gear 342. In this embodiment, the first and secondgear teeth 336, 338 do not directly engage and mate together. The piniongear 342 translates the movement from the second set of gear teeth 338to the first set of gear teeth 336. Thus, the second plurality of gearteeth 338 are configured to contact and rotate the pinion gear 342, andthe pinion gear 342 is configured to contact at least a portion of thefirst plurality of gear teeth 336 to cause the reducing member 316 tomove proximally in the direction of arrow B.

When the first and second trigger elements 320, 322 are moved relativeto one another (e.g., squeezed), the second trigger element 322 rotatesin the direction of arrow C and the reducing member 316 moves proximallyin the direction of arrow B. After the vertebrae or element has beenreduced, the reducing member 316 again is able to return to its originalposition such that the reducing member 316 moves distally in a directionopposite to arrow B and the second trigger element 322 rotates in adirection opposite to arrow C to return the first and second triggerelements 320, 322 to an expanded position.

In the embodiments depicted the second plurality of gear teeth 338 arepositioned on an end of the first or second trigger elements 320, 322,respectively. It should be understood, however, that the gear teeth 338may be positioned at any appropriate location so long as the first andsecond trigger elements 320, 322 are able to translate motion to thereducing element 316. Similarly, the coupling element 340 is positionedat an offset and opposite to the first and second gear teeth 336, 338,but it will be understood by those skilled in the art that the couplingelement 340 may be positioned at any suitable location in order to actas an appropriate fulcrum.

As shown in FIGS. 14B and 15B, the handle of the instrument 300 mayfurther include a ratchet mechanism 350. The ratchet mechanism 350 mayinclude an elongate member extending from an end of the first or secondtrigger elements 320, 322 and having a plurality of teeth 352 extendingtherefrom. On the opposite of the first or second trigger elements 320,322, a connector 354, for example, in the shape of a notch or catch (notshown) may engage at least one tooth from the plurality of teeth 352 onthe ratchet mechanism 350. In particular, the teeth 352 of the ratchetmechanism 350 may cooperate with the connector 354 as the triggerelements 320, 322 are squeezed together or towards one another. Theteeth 352 may be step-wise engaged with the connector 354. As thesuccessive teeth 352 engage with the connector 354, the first and secondtrigger elements 320, 322 are temporarily locked into place such thatthe first and second trigger elements 320, 322 may not move away fromone another. If an additional squeezing force is applied to the firstand second trigger elements 320, 322, however, the first and secondtrigger elements 320, 322 ratchet together. Thus, the operator is notrequired to continue to apply pressure to the trigger elements 320, 322to maintain a given position. In operation, the user may grasp theinstrument 300 in one hand, and the reducing member 316 may be movedproximally in the direction of B in a step-wise manner due to the use ofthe ratchet mechanism 350.

The ratchet mechanism 350 is connected to the first or second triggerelements 320, 322 with a suitable coupling element 356. This couplingelement 356 allows the secondary ratchet mechanism to be pivoted out ofposition or alignment with the connector 354 if a ratcheting action isnot required, no longer needed, or the reducing member 316 needs to beadvanced toward a proximal position. The handle portion including thefirst and second trigger elements 320, 322 may further include one ormore spring elements 360 positioned and configured to provide aspring-like action to extend the first and second trigger elements 320,322 away from one another. A suitable spring device may be selected byone of ordinary skill in the art.

Each of the first and second plurality of gear teeth 336, 338, gearteeth 344 on the pinion gear 342, and ratchet teeth 352 on the ratchet350 may comprise any suitable number or type of teeth, profile for theteeth (e.g., straight, curved), gear ratio, etc. as would be selected byone of ordinary skill in the art. The coupling elements 340, 346, 356may also include any suitable coupling devices known in the art, such aspins, hinges, or the like which allow the components to pivot or swivelaround an axis of rotation.

According to another embodiment, FIG. 16 depicts a threaded reducer 400.The threaded reducer 400 includes a reducing member 416 having agenerally cylindrical longitudinal body and a threaded portion 418 withat least a partially helical thread. The reducing member 416 and has aworking end 424 and a proximate end 426 extending from a distal end 412toward a proximal end 414. The reducing member 416 is generally hollowand defines a channel extending longitudinally through it from theworking end 424 to the proximate end 426.

The working end 424 of the reducing member 416 is adapted to receive aportion of a bone fastener including a tulip, yoke, or the like. Inparticular, the working end 424 is adapted to mate with an instrument ordevice, such as a fastener (e.g., a screw), a tulip, a rod, or the like.In this regard, the working end 424 may be forked and made up of a pairof opposing prongs 430, 432. The prongs 430, 432 each have an interiorwall which defines one or more catches (not shown) that are adapted tomate with at least a portion of a pedicle screw assembly. These catchesmay include the spring tabs 204 and ramped surfaces 210 discussed above.For example, the catches may have a shape that complements orcorresponds to the shape of the outer surface of a receiver element,fastener, tulip, yoke, or coupling element.

The reducing member 416 may be able to translate or move, for example,in a proximal direction when a rotation force is applied to the handle440. As a torque is applied to the handle 440 (e.g., clockwise), thethreaded portion 418 causes the reducing member 416 to move proximallyin the direction of arrow B. For example, the threaded portion 418 isconfigured to rotatably connect and engage a corresponding internalhelical thread (not shown) on an inner portion of the reducing member416 to cause translation of the reducing member 416. After the vertebraeor element has been reduced, a torque may be applied in the oppositedirect (e.g., counter-clockwise) the reducing member 416 is able toreturn to its original position such that the reducing member 416 movesdistally in a direction opposite to arrow B.

According to yet another embodiment, FIGS. 13A and B depicts a reducer500. The reducer 500 includes a reducing member 516 having a generallycylindrical longitudinal body and outer longitudinal member 518. Thereducing member 516 and has a working end 524 and a proximate end 526extending from a distal end 512 toward a proximal end 514. The reducingmember 516 is generally hollow and defines a channel extendinglongitudinally through it from the working end 524 to the proximate end526.

The working end 524 of the reducing member 516 is adapted to receive aportion of a bone fastener including a tulip, yoke, or the like. Inparticular, the working end 524 is adapted to mate with an instrument ordevice, such as a fastener (e.g., a screw), a tulip, a rod, or the like.In this regard, the working end 524 may be forked and made up of a pairof opposing prongs 530, 532. The prongs 530, 532 each have an interiorwall which defines one or more catches (not shown) that are adapted tomate with at least a portion of a pedicle screw assembly. These catchesmay include the spring tabs 204 and ramped surfaces 210 discussed above.For example, the catches may have a shape that complements orcorresponds to the shape of the outer surface of a receiver element,fastener, tulip, yoke, or coupling element.

The outer longitudinal member 518 has a body which is generally hollowand defines a channel extending longitudinally through it and is sizedand shaped to receive the reducing member 516 therein. The reducingmember 516 may be able to translate or move, for example, in a proximaldirection when a rotation force is applied to the handle 540. As atorque is applied to the handle 540 (e.g., clockwise), the reducingmember 516 move proximally into the longitudinal member 518.

According to another embodiment, a kit may be provided including any ofthe surgical instruments in combination with the devices and implantsdescribed herein. The kits may include one or more devices, tools,materials, and the like that may be useful in conjunction with theinstruments described. In particular, a kit may include a driver and oneor more fasteners, such as bone screws. A kit may include an inserterwith one or more fasteners (e.g., pedicle screws), tulips, rods, lockingcaps, for example, as described in U.S. Publication No. 2013/0018428. Akit may include a reducer with one or more fasteners (e.g., pediclescrews), tulips, rods, locking caps, etc. A kit may also include acombination of instruments including drivers, inserters, reducers,retractors, distractors, compressors, and the like, along with spinalimplants, devices, fixation elements, etc.

The surgical instruments and devices disclosed herein can be formed ofany suitable surgical material. Preferably, the surgical devices arecomprised of one or more physiologically compatible or biocompatiblematerials, for example, that have the property or characteristic of notgenerating injury, toxicity, or immunological reaction to livingtissues. Suitable physiologically compatible or biocompatible materialsinclude, but are not limited to plastics, such as polyether ether ketone(PEEK), polyether ketone ketone (PEKK), or ultra-high molecular weight(UHMW) polyethylene; metals, such as surgical stainless steel, titanium,titanium alloys, surgical steel, metal alloys; and other materials knownin the art. The surgical devices may also be made of a combination ofsuitable materials. In addition, the devices described herein may besterilized by any suitable methods including, but not limited to,autoclaving, ethylene oxide, radiation, cold sterilization (e.g.,hydrogen peroxide plasma), immersion sterilization, or a combinationthereof.

The surgical device may serve a number of different functions, forexample, including aiding insertion and securement of surgical devicesand implements (e.g., implants, screws, and the like), improvingperformance of surgical procedures, and other similar functions. Thedevices are adapted to permit insertion through minimally invasiveprocedures, and are especially suitable for spinal surgeries andprocedures. By way of example, the spinal surgeries may include, but arenot limited to, insertion of vertebral fusion and fixation devices,including rods, plates, cables, bone anchors, fasteners, such as screws,and the like, or any surgical procedure.

Although the invention has been described in detail and with referenceto specific embodiments, it will be apparent to one skilled in the artthat various changes and modifications can be made without departingfrom the spirit and scope of the invention. Thus, it is intended thatthe invention covers the modifications and variations of this inventionprovided they come within the scope of the appended claims and theirequivalents. It is expressly intended, for example, that all rangesbroadly recited in this document include within their scope all narrowerranges which fall within the broader ranges. It is also intended thatthe components of the various devices disclosed above may be combined ormodified in any suitable configuration.

What is claimed is:
 1. A method for inserting a surgical device, saidmethod comprising: attaching a surgical device to a distal tip of asurgical instrument, the surgical instrument including: a body having anouter housing and a handle, the outer housing having a longitudinal bodywith a channel extending therethrough and a distal tip configured toengage the surgical device; a shaft including a release shaft having adistal end configured to contact the surgical device and a second end,the shaft being housed within the channel of the outer housing, theshaft including a rack having a longitudinal body with a plurality ofteeth; a pinion having a plurality of teeth radially extending therefromand configured to mate with the plurality of teeth of the rack, and acam having a generally circular body with at least one projection whichis rotatably attached to the pinion and the body; and a trigger coupledto the handle and a linkage connecting the trigger to the second end ofthe shaft, and depressing the trigger such that the linkage moves theshaft and secures the surgical device to the distal tip.
 2. The methodof claim 1, wherein, when the trigger is fully depressed, the linkagemoves the rack linearly, which rotates the pinion and the cam andthereby moves the release shaft distally and releases the surgicaldevice.
 3. The method of claim 1, wherein the release shaft comprises atleast one tab which extends past the distal tip of the outer housingwhen the trigger is fully depressed.
 4. The method of claim 1, whereinthe trigger is connected to the second end of the shaft with a couplingelement which is retained in a longitudinal opening in the handle toprovide linear motion to the shaft.
 5. The method of claim 1, whereinthe distal tip includes at least two spring tabs configured to securethe surgical device.
 6. The method of claim 5, wherein the spring tabseach have a ramped surface configured to allow an axial force to couplethe surgical device and a ledge configured to retain at least a portionof the surgical device.
 7. The method of claim 6, wherein the outerhousing includes one or more spring cuts designed to allow the springtabs to flex when the surgical device is secured or released.
 8. Themethod of claim 1 further comprising a safety lock and a pin, the pinbeing receivable within an opening in the distal tip to lock the device.9. The method of claim 8, wherein the safety lock defines a non-linearopening, the safety lock is coupled to the pin with a coupling element,and the coupling element is positioned within the non-linear opening totranslate the motion from the safety lock to the pin.
 10. The method ofclaim 8 further comprising: unlocking the instrument by depressing thesafety lock; connecting the surgical device to the distal tip of theinstrument by applying an axial force; locking the surgical device tothe instrument by slightly depressing the trigger; performing a surgicalprocedure; and releasing the surgical device from the instrument byfully depressing the trigger.
 11. The method of claim 1, wherein thesurgical device is a screw, a tulip, a yoke, or a connector.
 12. Amethod for inserting a surgical device, said method comprising:attaching a surgical device to a distal tip of a surgical instrument,the surgical instrument including: an outer housing and a shaftcontained within the outer housing, a locking element connected to theshaft and having an engaging face with a first plurality of ratchetteeth, the locking element configured to move longitudinally along theshaft; the outer housing comprising a handle having a contacting facewith a second plurality of ratchet teeth sized and dimensioned tocorrespond with the first plurality of ratchet teeth; and a lockingbutton disposed on the locking element and configured to engage theshaft such that when the locking button is depressed, the firstplurality of ratchet teeth on the engaging face are contacting thesecond plurality of ratchet teeth on the contacting face and aratcheting mechanism is engaged, and depressing the trigger such thatthe linkage moves the shaft and secures the surgical device to thedistal tip.
 13. The method of claim 13, wherein the shaft furthercomprises a notch, and when the locking button is engaged in the notch,the first plurality of ratchet teeth on the engaging face teeth areseparated a distance from the second plurality of ratchet teeth on thecontacting face and the ratcheting mechanism is not engaged.
 14. Themethod of claim 13, wherein the locking element further comprises aspring and the spring surrounds the shaft, and wherein the spring isconfigured to keep the ratcheting mechanism engaged.